Snowy pattern highlights new forecasting technique for wintry weather

National Weather Service forecasts for the minimum, maximum… (National Weather Service…)

December 17, 2013|By Scott Dance, The Baltimore Sun

Recent brushes with snow have highlighted a new way to communicate wintry weather forecasts in the Baltimore area -- providing more detail on the range of possibilities for a snowfall, rather than a single best guess of accumulations.

The National Weather Service's Baltimore/Washington forecast office is running a pilot of a winter weather forecasting system that describes the minimum and maximum potential of a snowy system. In addition, the office's winter weather page details probabilities of any given amount of snow accumulation at cities and towns across the state and region.

For example, ahead of Saturday's snowfall, the forecasters were predicting the possibility of no snow at all for much of the region, or the chance that the system could overperform and bring as much as 8 inches across parts of Carroll and Baltimore counties. The most likely forecast, meanwhile, was a range of 4-6 inches for those areas, with lower totals to the south and east.

Officials explained the forecasting system to reporters at their Sterling, Va., forecast office Friday. The added detail is important in a region where slight shifts in the line between rain and snow can affect millions of people, they said.

They acknowledged that their forecasts inform decisions that are often expensive, including road treatment and event cancellations. A key example of that occurred last March 6, when forecasters were calling for the potential of as much as a foot of snow in some areas, prompting school closures and road salting, but little more than a slushy dusting fell.

"It's been called for that we need to do better," said Chris Strong, warning coordination meteorologist at the Sterling office.